Surgical techniques for stabilizing bones, such as vertebra, are known. In some approaches, bone screw assemblies are driven into pedicles of two or more vertebrae and a spinal rod is placed within yokes of the bone screw assemblies and secured therewith. The bone screw assemblies and spinal rod stabilize the vertebrae in conjunction with one or more implants positioned in the intervertebral disc space. To further stabilize the vertebrae, a column of bone graft material can be placed in the posterolateral gutter of each vertebrae between the spinous process and transverse process of the vertebra. The column of bone graft material is oriented to extend generally parallel to the spinal rod and bonded to the transverse processes of the vertebrae. This procedure may be referred to as a posterolateral fusion (PLF). The bone graft material encourages bone growth into and along the column which produces a rigid, boney structure spanning the vertebrae and providing additional support against relative movement of the vertebrae. Traditionally, access to the vertebrae is obtained using a “full open” procedure that involves making a long incision parallel to the patient's spine and retracting tissues surrounding the vertebrae. The full open approach may not be desirable in some instances, where the long incision may increase tissue trauma and patient recovery time.